Secondary electric clock



June 1 1926. 158K 34? E. G. STALNAKER SECONDARY-ELECTRIC CLOCK Filed Nov. 5, 1924 Patented June 1, 1926.

UNITED? STATES PATENT OFFICE.

EARL G. STALNTAKER, OF CHICAGO, ILLINOIS.

Application filed November This invention relates to improvements in secondary electrically controlled clocks and has for its principal object to provide a simple and efficient means for accurately actuating the clock mechanism.

As is well known in the art, a primary or master clock is employed for controlling the actuation of the clock mechanisms of the secondary clocks and usually the electric impulses which are controlled by the master clock are employed for winding the spring mechanism of the secondary clocks and for also releasing the escapement of the latter. Frequently the secondary clocks do not operate simultaneously with the master clock,

thus resulting in a difference between the time shown by the master clock and that shown by the secondary clocks. Where accuracy is necessary, especially in connection with railroads and the like, the clock mech anism is ordinarily very complicated as well as expensive in order to obtaln the desired result.

One of the principal objects of the present invention is to provide a. secondary electric clock which is of such construction as to overcome the above disadvantages and further eliminate the use of the customary winding springs, for the purpose of actuating the clock mechanism.

Another important object is to provide a secondary electric clock of the above mentioned character, wherein the escapement is utilized for the purposes of actuating the clock mechanism, an electro-magnetic mechanism being associated with the escapement for'actuating the same in-one direction, the weight of the armature being adapted to cause the operation of the escapement in the opposite direction when the electromagnet is deenergized.

A still further object of the invention is to provide a secondary electric clock of the above mentioned character, which is simple in construction, inexpensive, strong and durable and furthermore adapted for the purposcs for which it is designed.

Other obiects and advantages of this invention will become apparent during the course of the following description.

In the accompanying drawing forming a part of this specification and in which like numerals designate like parts throughout the same:

Figure 1 is a front elevation of the sec- SECONDARY ELECTRIC CLOCK.

5, 1924. s ri rno. 747,934.,

ondary electric clock embodying my inventron with parts broken away. Figure 2 is a side elevation.

. Figure 3 is an enlarged fragmentary detail of the toothed second wheel, the escapement, and the electrically controlled mechanism associated with the escapement, and

Figure 4 is a fragmentary enlarged detail of the toothed wheel and the escapement.

In the drawing, wherein for the purpose of illustration is shown the preferred embodiment of my invention, the numeral 1 designates a frame in which is supported a series of shafts operatively connected by a train of gearing in the usual manner. The shafts include an escapement shaft 2 which carries the second hand 3. Also keyed on the shaft 2 is the toothed escapement wheel 4;, the teeth 5 thereof being substantially of Pivotally supported in' the frame 1 adja-' cent the lateral extension 8 is a shaft 12 and carried thereby is the escapement 13. The escapement 13 includes a pair of arms 14 and 15 respectively which are disposed on opposite sides of the escapement wheel 4. The

free ends of the arms 14 and 15 are disposed downwardly and terminate in the pallets 16 The and 17 respectively, the same being adapted for cooperation with the teeth 5 of the escapement wheel 4 in the manner hereinafterto be more fully described. Each of the pallets is of such shape as to be narrower than a single tooth of the escapement wheel 4 so' that a caniming action results when the faces of the pallets engage the sloping portions of the teeth. v

Secured on the'shaft 12 by the set screw 18 is the weighted armature 19 which is preferably of a soft iron material. The upper forward corner of the armature 19 is beveled as illustrated at 20 for cooperation with the beveled face 11 of the core 10, The

purpose of providing the beveled faces on the end of the core of the electromagnct and the adjacent portion of the armature is to enable the electro-magnet mechanism to properly function in carrying out the purposes for which the same is designed regard less of the position of the clock.

The operation of the clock mechanism may be briefly stated as follows :Assuming that the escapement and the armature associated therewith are disposed in the position as shown in Figure 1 of the drawing wherein the pallet 17 is in engagement with one of the teeth 5 of the escapement wheel 4, when the magnet 9 is energized or excited, the armature 19 will respond to the impulse and move from the dotted line position shown in Figure 3 to the full line position shown in the same figure into engagement with the core 10 so that the beveled faces of the core and armature are in engagement with each other. This movement simultaneously causes a downward movement of the arm 14 of the escapement 13 and the pallet 16 so that the bottom face of the pallet 16 will engage the sloping face of one of the teeth of the eseap ement wheel causing the escapement. wheel to move a distance corresponding to one half of-one of the teeth. lVhen the pallet 16 is in engagement with one of the teeth of the escapement wheel, the pallet 17 is out of engagement with the teeth.

As soon as the magnetized impulse ceases, the weight of the armature 19 will by gravity cause the-arm 15 of the escapement 13 to move downwardly, simultaneously bringing the bottom face of the pallet 17 into engagement with the sloping face of one of the teeth of the escapement wheel whereby the latter is moved an additional distance corresponding to the other half of one of the teeth. t is obvious that when the escapement 13 has completed its oscillatory movement, the escapement wheel will have moved a distance equal to one sixtieth of the circumference of the wheel, it being understood of course that the escapement wheel is provided with sixty teeth.

As stated above, the actuation of the elect-romalgnet is controlled by a master or primary clock in the manner well known in the art.

To further illustrate the manner in which the second hand 3 is operated, attention is called to Figure 3 of the drawing. wherein the second hand 3 is normally in the position as shown at A. when the pallet 16 engages one of the teeth of the escapement wheel in the manner above described, the second hand is moved to the position as shown at B and when the pallet 17 engages the adjacent tooth of the escapement wheel.

the second hand moves to the position shown at C, the distance between the positions A and C being equivalent to one second. Thus, the second hand is caused to move a half second at a time.

It will thus be seen from the foregoing description, that a secondary electric clock has been provided wherein the use of the usual winding spring is entirely eliminated and the escapement serves a two fold function, as an escapement governor and further as a means for rotating the escapement wheel. Secondary electric clocks thus constructed will accurately indicate the exact time as that shown by the master or primary clock, and furthermore it is not necessary that the clock be supported in an accurate vertical position on a wall in order that the several parts of the actuating mecha nism may properly function.

- \Vhile I have shown the preferred embodiment of my invention, it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirit of the invention and the scope of the appended claim.

Having thus described the invention. what I claim is In a clock mechanism, in combination, a toothed wheel arranged for propelling the remainder of the clock mechanism, an oscillatory pallct shaft disposed adjacent and above the wheel, an escapement carried by said shaft and including a pair of :I'Ilns. terminating in pallets disposed at predetermined angles with respect to the body portion ofthe escapement and adapted for engagement with the teeth of the wheel intermittently. a weighted armature block adjustably mounted on said shaft, retaining means for said block, whereby it may be disposed obliquely with respect to the axis of said shaft, and an electro-magnet disposed adjacent said block, said magnet including a core disposed at an obtuse angle with respect to said block, the free end of .said core being beveled at one corner of said block for co-action with the first named bevel, one of the pallets being adapted to engage the toothed wheel for moving the same a distance corresponding substantially one-half of a tooth. when the electro-magnct is energized. the other pallet being adapted to advance the toothed wheel for a distance corresponding to another half of a tooth by the weight of the armature. when the latter is returned to its normal position upon the energization of the magnet.

In testimony whereof I afhx my signature.

EARL G. SIALNAKER. 

